THE SPERMATIC CORD 



1259 



membrane, whose cells contain considerable quantities of a yellowish-browTi pigment, and also 

 contribute a secretion to the seminal fluid. In addition to having this function the vesiculae 

 also serve as receptacles for the spermatozoa. They arise as diverticula from the embryonic 

 ductus deferens, and it is worthy of note that a number (4 or 5) of similar but quite small diver- 

 ticula arise from the upper part of each ductus ejaculatorius. 



Vessels and nerves. — The artery supplying the ductus deferens is the a. deferentiaUs, a 

 branch of the superior vesical. It accompanies the ductus to the tail of the epididymis and also 

 gives a branch to the vesicula seminalis. The latter also receives branches from the middle 

 hsemorrhoidal and inferior vesical arteries. The deferential vein accompanies the ductus 

 deferens to the base of the bladder where it breaks up into a plexus that communicates with 

 the seminal venous plexus formed by the veins from the seminal vesicles. This joins with the 

 vesical and pudendal plexus and so communicates with the hypogastric vein. The lymphatics 

 of the ductus deferentes and seminal vesicles pass to the external iliac and hypogastric 

 nodes. The nerves of both structures are derived from the hypogastric plexus. 



The spermatic cord. — In its descent through the inguinal canal into the 

 scrotum the testis necessarily drags after it the ductus deferens and the testicular 

 vessels and nerves, these structures coming together at the abdominal inguinal 



Fig. 1021. — Cross-section of the Spermatic Cord. 



A. spermatica interna 

 K. spermaticus int. 



Lymph vessel 



Vv. spermaticae int. 



Fascia cremasterica 



Tunica vag- 

 inalis 

 communis 



/Lymph vessel 



Ductus deferens 



Vv. spermaticae int 



A. et V. deferentiaUs 



V. spermatica ext. 



ring to form what is termed the spermatic cord [funiculus spermaticus]. This 

 structure extends, therefore, from the abdominal inguinal ring, through the in- 

 guinal canal and the neck of the scrotal sack to the testis, and is enclosed within 

 the same investing layers as the testis. 



Thus as it emerges from the subcutaneous inguinal ring it receives an investment of con- 

 nective tissue continuous with the intercrural fibres and the aponeurosis of the external oblique 

 muscle. This cremasteric fascia has beneath it bands of striated muscle tissue, the external 

 cremaster muscle (fig. 1021), especially developed on the posterior surface of the cord and con- 

 tinuous with the internal obhque muscle of the abdomen, and within these is an indistinct 

 layer of connective tissue, the tunica vaginalis communis, which is received at the abdominal 

 inguinal ring where it is continuous with the fascia transversaUs. 



Within the sheath thus formed there is a matrix of connective tissue, usually 

 containing considerable amounts of fat and strands of non-striated muscle tissue, 

 which form what is termed the inlernal cremaster muscle (funicular portion), 

 and imbedded in this connective tissue are the various essential constituents of 

 the cord. These are as follows (figs. 1017, 1021) : (1) the ductus deferens, occupy- 

 ing the posterior surface of the cord and having associated with it the deferential 

 artery and veins and the deferential plexus of nerve fibres; (2) the internal 

 spermatic artery, which occupies the axis of the cord and is surrounded by (3) the 

 internal spermatic veins, which form a complicated network, known as the pam- 



